1. Field of the Invention
The present invention relates to a digital broadcast/analog broadcast receiving apparatus and method for receiving a digital broadcast signal and an analog broadcast signal and outputting a video signal and an audio signal, and particularly to a digital broadcast/analog broadcast receiving apparatus and method for multiplexing a closed caption into a video signal and producing an output.
2. Description of the Related Art
A conventional digital broadcast/analog broadcast receiving apparatus includes a circuit for receiving a digital broadcast signal and a circuit for receiving an analog broadcast signal. When a channel selected is digital broadcast, the circuit for digital broadcast is used to convert the digital broadcast signal and a video signal, an audio signal and a closed caption of an analog mode are outputted. When the channel selected is analog broadcast, the circuit for analog broadcast signal is used to output a video signal, an audio signal and a closed caption of an analog mode.
In terrestrial analog television broadcasting of North America (NTSC system: National Television System Committee system), the closed caption is delivered by inserting closed caption information into the twenty-first scan line of the video signal in the side of a broadcast station. A receiving apparatus (a digital broadcast/analog broadcast receiving apparatus or an analog broadcast receiving apparatus having an analog broadcast receiving function) extracts and analyzes the closed caption information inserted into the video signal received and inserts the closed caption information back into the video signal and outputs the video signal to a display device. The display device displays program video and the closed caption on a screen based on the video signal. A method for delivering the closed caption by the twenty-first scan line (LINE. 21) of the video signal thus is defined by EIA-608.
In analog broadcast, a maximum of four languages can be used as a first to a fourth closed captions (CC1 to CC4). A first language (main language) is allocated to the first closed caption (closed caption 1 (CC1)) and a second language (sub language) is allocated to the third closed caption (closed caption 3 (CC3)).
On the other hand, in ground wave digital broadcasting of North America (ATSC system: Advanced Television Systems Committee system) similarly, a closed caption is delivered by data of “userdata” in an MPEG stream. Data including the closed caption delivered thus is called DTVCC and is defined by EIA-708B.
In the DTVCC, a maximum of six languages can be used as a first to a sixth caption service data (CSD1 to CSD6). A first language (main language) is allocated to thee first caption service data (caption service data 1 (CSD1)) and a second language (sub language) is allocated to the second caption service data (caption service data 2 (CSD2)).
However, in the conventional digital broadcast/analog broadcast receiving apparatus, as shown in FIG. 5, when a channel selected is digital broadcast, any of the caption service data 1 to 6 (CSD1 to CSD6) is selected and is outputted as a closed caption 1 (CC1) for analog broadcast. When all the caption service data are associated with one closed caption in this manner, a viewer must operate operation means (such as a remote control unit) of the digital broadcast/analog broadcast receiving apparatus at the time of changing the caption service data.
On the other hand, when the channel selected is analog broadcast, closed captions 1 to 4 (CC1 to CC4) inputted to the receiving apparatus are outputted as the closed captions 1 to 4 (CC1 to CC4) as they are as shown in FIG. 6. As a result, the viewer must operate operation means of the display device (such as a closed caption selection button) at the time of changing the closed caption.
As described above, when the viewer changes the closed caption, the operation means operated varies depending on whether the channel selected is digital broadcast or analog broadcast, and the operation becomes troublesome.
Various digital broadcast/analog broadcast receiving apparatus have been proposed conventionally, and there is a technique such disclosed in JP-A-2002-044616. However, no method for solving the problem described above is disclosed.